HPLIP does not use usblp, instead HPLIP uses libusb. Libusb uses the "/dev/bus/usb/xxx/xxx" device node instead of the "/dev/usb/lp0" device node.
Since usblp and libusb cannot use the same device node, any HPLIP device I/O usage (ie: scanning, printing or faxing) will remove usblp from that device node. Once usblp has been removed it cannot be restored except by another UDEV plug-n-play event. If you are using CUPS this means in general you should always use the HPLIP's "hp" backend (ie: "hp:/usb/...") instead of the standard CUPS "usb" backend (ie: "usb://..."). The "hp" backend will always use the libusb device node. If you try to use the "usb" backend the "dev/usb/lp0" device node may not be available. -dave > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Peter Robins > Sent: Monday, October 15, 2007 4:30 AM > To: hplip-help@lists.sourceforge.net > Subject: [Hplip-help] /dev/usb/lp0 deleted after every print job > > I've searched through the archive and find a number of > similar threads, for example > http://thread.gmane.org/gmane.comp.printing.hplip.user/2177, > but I can't find any resolution. > > I've installed hplip using the latest Slackware binaries, > which I'm using without any modifications on my part. My > printer is a F2180. As with the other thread, I turn on the > printer and udev/kernel creates /dev/usb/lp0 and appropriate > messages are written to /var/log/messages. I then print out > from my application (various KDE programs) and the job prints > correctly. > However, /dev/usb/lp0 is then deleted, and > > hpiod: removing usblp driver interface=1 for > hp:/usb/Deskjet_F2100 io/hpiod/device.cpp 504 > kernel: drivers/usb/class/usblp.c: usblp0: removed > > is written to /var/log/messages. So when I try and print the > next file, the device no longer exists and the printout > doesn't work. The printer has to be switched off and on > again, so that udev recreates /dev/usb/lp0. > > However, I do not have this problem if I print via a file. > So, if I print from my application to a PS file, and then > print that to /dev/usb/lp0 with a similar gs cmd to the one > the HP driver uses, such as: > > gs -dSAFER -sDEVICE=ijs -sIjsServer=hpijs > -sDeviceManufacturer=HEWLETT-PACKARD -sDeviceModel="deskjet > 3320" -dIjsUseOutputFD -sOutputFile=/dev/usb/lp0 -dNOPAUSE > -sPAPERSIZE=a4 -r300 -- print.ps > > then it prints fine and /dev/usb/lp0 is not deleted. > > I know next to nothing about how all these pieces of software > fit together (or not), but from the entry in > /var/log/messages it looks as though hpiod is telling > udev/kernel that the printer is switched off. I can see that > it might need to send a 'printer idle' msg after each print > job, but why 'printer off'? > > In case it's relevant, I should perhaps also say that I have > not yet installed pyqt (I need to rejuggle the partitions to > make room, and don't have time for that at the moment), so am > not using the full hplip software. > > -------------------------------------------------------------- > ----------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and > a browser. > Download your FREE copy of Splunk now >> > http://get.splunk.com/ _______________________________________________ > HPLIP-Help mailing list > HPLIP-Help@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/hplip-help > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ HPLIP-Help mailing list HPLIP-Help@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/hplip-help
